1. Field of the Invention
The present invention relates to a recording method and recording apparatus capable of suppressing drying of ink in inkjet recording heads.
2. Description of the Related Art
Japanese Patent Application Laid-Open No. 2000-255053 discusses a method, in a printing apparatus in which inkjet recording heads are fixedly arranged in a line in the direction of sheet conveyance, for maintaining humidity of the inkjet recording heads and suppressing drying of ink by continuously supplying humidified gas toward a nozzle of each of the recording heads from the upstream side thereof.
A Sheet such as paper that has an equilibrium moisture content (the state at which the sheet is neither gaining nor losing moisture) that changes according to a humidity in the air: the sheet absorbs moisture at higher humidity, and releases moisture at lower humidity. When a sheet is fed to an area near recording heads, the area having a high humidity due to humidified air supplied thereto, the sheet starts to absorb moisture.
As a result, some drop in humidity in the atmosphere occurs, and may disturb appropriate moisturization of the recording heads. Especially in a configuration with a plurality of recording heads fixedly arranged in a line in the direction along which humidified air is introduced, it takes some time for the humidified gas to flow down the line, and the moisture is absorbed by the recording heads in the order arranged. This tends to make the humidity retention of the downstream recording heads insufficient.
In view of the above problem, a first object of the present invention is to provide a recording method and recording apparatus capable of maintaining recording heads at an appropriate moisture level and suppress drying of ink during recording operation. The drying level of ink during recording operation of a recording heads changes depending on various conditions for the recording. For example, a sheet has a different equilibrium moisture content depending on the type of the sheet for the same ambient conditions. The sheets for inkjet printing are generally formed of base paper such as resin coated paper (hereinafter, referred to as RC sheet) and paper based paper (hereinafter, referred to as baryta paper).
The RC paper is formed of base paper coated with resin, and absorbs less moisture in the fiber of the paper than baryta paper. In other words, different types of sheets have different moisture absorption properties (different amount and rate of moisture absorption). Accordingly, when a sheet having a moisture absorption property larger than expected is used, since it takes a period of time for humidified gas to flow down the line of recording heads, which is supplied from the upstream side of the recording heads, and moisture in the gas is absorbed by the sheet, the humidity of the recording heads on downstream side is likely to become insufficient.
In view of the above problem, a second object of the present invention is to provide a recording method and recording apparatus capable of moisturizing recording heads without fail independently of the recording conditions.